5/1/15 - Bash *

Today, I was trying to figure out where a console.log debug statement that I no longer needed was coming from. I asked Sam for a bit of help with grep and ended up learning a ton of interesting stuff about bash in the process. Here are the commands I did:

1. $ grep --help | less - Pipes the help output to the less, which paginates whatever is passed into it so the console isn't spewing tons of text all at once.
2. $ grep console.log js/app.js tests/* - From the help output, I learned that you can search in multiple files at once by listing them after the search string. Sam also explained how the * special character actually expands to all the files in the given scope and passes their paths into the program.
3. I didn't believe him, so I wrote a quick ruby program:
   p ARGV (that's the whole program--I love ruby!) and ran $ args.rb *
   Sure enough, this outputted ['args.rb', 'arr.rb', ...] (also, 'args.rb' is included because it's a file in the scope of * and not because the run command was ruby args.rb ...)
4. The problem with the grep command I used was that it didn't tell me the line numbers for the console.log matches. I looked through the help some more, and eventually ran $ grep console.log js/app.js tests/* -n.
   This outputted a nice list:

   js/app.js:164:        console.log(bookPath);
   js/app.js:176:                console.log('wrote: ' + this.result);
   js/app.js:334:                console.log("error loading json from url " + url);
   js/app.js:335:                console.log(e);
   js/app.js:338:                console.log("timeout loading json from url " + url);
   js/app.js:339:                console.log(e);
   

   and I was able to identify the line I wanted gone.
5. So today I learned: bash and grep are pretty neat!